High foaming nonionic surfactant based liquid detergent

ABSTRACT

A high foaming, light duty liquid detergent with desirable cleansing properties and mildness to the human skin composing: a water soluble nonionic surfactant; a ethoxylated alkyl ether sulfate anionic surfactant, a zwitterionic betaine surfactant and the balance being water.

RELATED APPLICATION

This application is a continuation in part application of U.S. Ser. No.8/091,513, filed Jul. 9, 1993 which in turn is a continuation in partapplication of U.S. Ser. No. 07/893,138 filed on Jun. 3, 1992, bothabandoned.

BACKGROUND OF THE INVENTION

The present invention relates to novel light duty liquid detergentcompositions with high foaming properties, containing a nonionicsurfactant, an ethoxylated alkyl ether sulfate surfactant, azwitterionic betaine surfactant and the balance being water.

Nonionic surfactants are in general chemically inert and stable towardpH change and are therefore well suited for mixing and formulation withother materials. The superior performance of nonionic surfactants on theremoval of oily soil is well recognized. Nonionic surfactants are alsoknown to be mild to human skin. However, as a class, nonionicsurfactants are known to be low or moderate foamers. Consequently, fordetergents which require copious and stable foam, the application ofnonionic surfactants is limited. There have been substantial interestand efforts to develop a high foaming detergent with nonionicsurfactants as the major ingredient. Little has been achieved.

The prior art is replete with light duty liquid detergent compositionscontaining nonionic surfactants in combination with anionic and/orbetaine surfactants wherein the nonionic detergent is not the majoractive surfactant, as shown in U.S. Pat. No. 3,658,985 wherein ananionic based shampoo contains a minor amount of a fatty acidalkanolamide. U.S. Pat. No. 3,769,398 discloses a betaine-based shampoocontaining minor amounts of nonionic surfactants. This patent statesthat the low foaming properties of nonionic detergents renders its usein shampoo compositions non-preferred. U.S. Pat. No. 4,329,335 alsodiscloses a shampoo containing a betaine surfactant as the majoringredient and minor amounts of a nonionic surfactant and of a fattyacid mona- or di-ethanolamide. U.S. Pat. No. 4,259,204 discloses ashampoo comprising 0.8-20% by weight of an anionic phosphoric acid esterand one additional surfactant which may be either anionic, amphoteric,or nonionic. U.S. Pat. No. 4,329,334 discloses an anionic-amphotericbased shampoo containing a major amount of anionic surfactant and lesseramounts of a betaine and nonionic surfactants.

U.S. Pat. No. 3,935,129 discloses a liquid cleaning composition based onthe alkali metal silicate content and containing five basic ingredients,namely, urea, glycerin, triethanolamine, an anionic detergent and anonionic detergent. The silicate content determines the amount ofanionic and/or nonionic detergent in the liquid cleaning composition.However, the foaming property of these detergent compositions is notdiscussed therein.

U.S. Pat. No. 4,129,515 discloses a heavy duty liquid detergent forlaundering fabrics comprising a mixture of substantially equal amountsof anionic and nonionic surfactants, alkanolamines and magnesium salts,and, optionally, zwitterionic surfactants as suds modifiers.

U.S. Pat. No. 4,224,195 discloses an aqueous detergent composition forlaundering socks or stockings comprising a specific group of nonionicdetergents, namely, an ethylene oxide of a secondary alcohol, a specificgroup of anionic detergents, namely, a sulfuric ester salt of anethylene oxide adduct of a secondary alcohol, and an amphotericsurfactant which may be a betaine, wherein either the anionic ornonionic surfactant may be the major ingredient.

The prior art also discloses detergent compositions containing allnonionic surfactants as shown in U.S. Pat. Nos. 4,154,706 and 4,329,336wherein the shampoo compositions contain a plurality of particularnonionic surfactants in order to effect desirable foaming and detersiveproperties despite the fact that nonionic surfactants are usuallydeficient in such properties.

U.S. Pat. No. 4,01 3,787 discloses a piperazine based polymer inconditioning and shampoo compositions which may contain all nonionicsurfactant or all anionic surfactant.

U.S. Pat. No. 4,450,091 discloses high viscosity shampoo compositionscontaining a blend of an amphoteric betaine surfactant, apolyoxybutylenepolyoxyethylene nonionic detergent, an anionicsurfactant, a fatty acid alkanolamide and a polyoxyalkylene glycol fattyester.

U.S. Pat. No. 4,595,526 describes a composition comprising a nonionicsurfactant, a betaine surfactant, an anionic surfactant and a C₁₂ -C₁₄fatty acid monoethanolamide foam stabilizer.

However, none of the above-cited patents discloses a high foaming,nonionic based, liquid detergent composition containing water, anonionic surfactant, a supplementary high foaming ethoxylated alkylether sulfate anionic surfactant and a supplementary foamingzwitterionic surfactant selected from betaine type surfactants as thethree essential ingredients, wherein the composition does not containany amine oxide, calcium carbonate, polymeric or clay thickeners,abrasive, clays, silicas, alkyl glycine surfactant, cyclic imidiniumsurfactant, fatty acid, metal salt of a fatty acid, alkyl carboxylatesurfactant, alkyl sulfate surfactant, alkyl or aryl sulfonatesurfactant, polymeric surfactant, fumed silica, organophilic organicclay or smectite clay, wherein the concentration of the nonionicsurfactant is always greater than the concentration of the ethoxylatedalkyl ether sulfate surfactant or the betaine surfactant.

SUMMARY OF THE INVENTION

It has now been found that a high foaming liquid detergent can beformulated with a nonionic surfactant which has desirable cleaningproperties and mildness to the human skin.

An object of this invention is to provide novel, liquid aqueousdetergent compositions containing a nonionic surfactant, an ethoxylatedalkyl ether sulfate anionic surfactant, and a zwitterionic betainesurfactant, wherein the composition does not contain amine oxide, alkalimetal carbonate, polymeric or clay thickeners, clays, abrasives, alkylglycine surfactants, cyclic imidinium surfactants, silicas, fatty acidor a metal salt of a fatty acid, alkyl carboxylate surfactant, alkylsulfate surfactant, alkyl or aryl sulfonate surfactant, polymericsurfactant, fumed silica, organophilic organic clay or smectite clay,wherein the concentration of the nonionic surfactant is always greaterthan the concentration of the ethoxylated alkyl ether sulfate surfactantor the betaine surfactant.

Still another object of this invention is to provide a novel, liquiddetergent with desirable high foaming and cleaning properties which ismild to the human skin.

Additional objects, advantages and novel features of the invention willbe set forth in part in the description which follows, and in part willbecome apparent to those skilled in the art upon examination of thefollowing or may be learned by practice of the invention. The objectsand advantages of the invention may be realized and attained by means ofthe instrumentalities and combinations particularly pointed out in theappended claims.

To achieve the foregoing and other objects and in accordance with thepurpose of the present invention, as embodied and broadly describedherein the novel, high foaming, light duty liquid detergent of thisinvention comprises three essential surfactants: a water soluble,ethoxylated, nonionic surfactant; a foaming water soluble, zwitterionicsurfactant selected from the class of betaines; and an ethoxylated alkylether sulfate surfactant, wherein the ingredients are dissolved in anaqueous vehicle, and the composition does not contain any amine oxide oralkanolamide ingredients.

More specifically, the present invention relates to a high foaming,nonionic based, liquid detergent comprising a nonionic surfactantselected from the group consisting of water soluble primary aliphaticalcohol ethoxylates, secondary aliphatic alcohol ethoxylates, alkylphenol ethoxylates and alcohol ethylene oxide propylene oxidecondensates; a water soluble zwitterionic betaine surfactant; and anethoxylated alkyl ether sulfate surfactants, wherein the ingredients aredissolved in an aqueous vehicle.

The total amount of surfactants may constitute about 10%-55%, preferablyabout 20%-40%, most preferably 25%-35%, by weight of the liquidcomposition.

DETAILED DESCRIPTION OF THE INVENTION

The high foaming nonionic based light duty liquid detergent compositionsof the instant invention comprise approximately by weight: 13 to 25 wt.% of a water soluble nonionic surfactant; 8 to 16 wt. % of anethoxylated alkyl ether surfactant; and 2 to 12 wt. % of a betainesurfactant; and 47 to 80 wt. % of water, wherein the compositions do notcontain any amine oxides, calcium carbonate, polymeric or claythickeners, abrasives, clays, silicas, alkyl glycine surfactants, cyclicimidinium surfactants, fatty acid, metal salt of a fatty acid, alkylcarboxylate surfactant, alkyl sulfate surfactant, alkyl or arylsulfonate surfactant, polymeric surfactant, fumed silica, organophilicorganic clay or smectite clay, wherein the concentration of the nonionicsurfactant is always greater than the concentration of the ethoxylatedalkyl ether sulfate surfactant or the betaine surfactant.

The nonionic surfactant which constitutes the major ingredient in theliquid detergent composition is present in amounts of about 13 to 25%,preferably 15 to 20% by weight of the composition and provides superiorperformance in the removal of oily soil and mildness to human skin.

The water soluble nonionic surfactants utilized in this invention arecommercially well known and include the primary aliphatic alcoholethoxylates, secondary aliphatic alcohol ethoxylates, alkylphenolethoxylates and ethylene-oxidepropylene oxide condensates on primaryalkanols, such a Plurafacs (BASF) and condensates of ethylene oxide withsorbitan fatty acid esters such as the Tweens (ICI). The nonionicsynthetic organic detergents generally are the condensation products ofan organic aliphatic or alkyl aromatic hydrophobic compound andhydrophilic ethylene oxide groups. Practically any hydrophobic compoundhaving a carboxy, hydroxy, amido, or amino group with a free hydrogenattached to the nitrogen can be condensed with ethylene oxide or withthe polyhydration product thereof, polyethylene glycol, to form a watersoluble nonionic detergent.

The nonionic detergent class includes the condensation products of ahigher alcohol (e.g., an alkanol containing about 8 to 18 carbon atomsin a straight or branched chain configuration) condensed with about 5 to30 moles of ethylene oxide, for example, lauryl or myristyl alcoholcondensed with about 16 moles of ethylene oxide (EO), tridecanolcondensed with about 6 to moles of EO, myristyl alcohol condensed withabout 10 moles of EO per mole of myristyl alcohol, the condensationproduct of EO with a cut of coconut fatty alcohol containing a mixtureof fatty alcohols with alkyl chains varying from 10 to about 14 carbonatoms in length and wherein the condensate contains either about 6 molesof EO per mole of total alcohol or about 9 moles of EO per mole ofalcohol and tallow alcohol ethoxylates containing 6 EO to 11 EO per moleof alcohol.

A preferred group of the foregoing nonionic surfactants are the Neodolethoxylates (Shell Co.), which are higher aliphatic, primary alcoholcontaining about 9-15 carbon atoms, such as C₉ -C₁₁ alkanol condensedwith 8 moles of ethylene oxide (Neodol 91-8), C₁₂₋₁₃ alkanol condensedwith 6.5 moles ethylene oxide (Neodol 23-6.5), C₁₂₋₁₅ alkanol condensedwith 12 moles ethylene oxide (Neodol 25-12), C₁₄₋₁₅ alkanol condensedwith 13 moles ethylene oxide (Neodol 45-13), and the like. Suchethoxamers have an HLB (hydrophobic lipophilic balance) value of about 8to 15 and give good O/W emulsification, whereas ethoxamers with HLBvalues below 8 contain less than 5 ethyleneoxide groups and tend to bepoor emulsifiers and poor detergents.

Additional satisfactory water soluble alcohol ethylene oxide condensatesare the condensation products of a secondary aliphatic alcoholcontaining 8 to 18 carbon atoms in a straight or branched chainconfiguration condensed with 5 to 30 moles of ethylene oxide. Examplesof commercially available nonionic detergents of the foregoing type areC₁₁ -C₁₅ secondary alkanol condensed with either 9 EO (Tergitol 15-S-9)or 12 EO (Tergitol 15-S-12) marketed by Union Carbide.

Other suitable nonionic detergents include the polyethylene oxidecondensates of one mole of alkyl phenol containing from about 8 to 18carbon atoms in a straight- or branched chain alkyl group with about 5to 30 moles of ethylene oxide. Specific examples of alkyl phenolethoxylates include nonyl phenol condensed with about 9.5 moles of EOper mole of nonyl phenol, dinonyl phenol condensed with about 12 molesof EO per mole of dinonyl phenol, dinonyl phenol condensed with about 15moles of EO per mole of phenol and di-isoctylphenol condensed with about15 moles of EO per mole of phenol. Commercially available nonionicsurfactants of this type include Igepal CO-630 (nonyl phenol ethoxylate)marketed by GAF Corporation.

Condensates of 2 to 30 moles of ethylene oxide with sorbitan mono- andtri- C₁₀ -C₂₀ alkanoic acid esters having a HLB of 8 to 15 also may beemployed as the nonionic detergent ingredient in the described shampoo.These surfactants are well known and are available from ImperialChemical Industries under the Tween trade name. Suitable surfactantsinclude polyoxyethylene (4) sorbitan monolaurate, polyoxyethylene (4)sorbitan monostearate, polyoxyethylene (20) sorbitan trioleate andpolyoxyethylene (20) sorbitan tristearate.

The water-soluble zwitterionic surfactant, which is also an essentialingredient of present liquid detergent composition, constitutes about 2to 12%, preferably 3 to 10%, by weight and provides good foamingproperties and mildness to the present liquid detergent. Thezwitterionic surfactant is a water soluble betaine having the generalformula: ##STR1## wherein R₁ is an alkyl group having 10 to about 20carbon atoms, preferably 12 to 16 carbon atoms, or the amido radical:##STR2## wherein R is an alkyl group having about 9 to 19 carbon atomsand a is the integer 1 to 4; R₂ and R₃ are each alkyl groups having 1 to3 carbons and preferably 1 carbon; R₄ is an alkylene or hydroxyalkylenegroup having from 1 to 4 carbon atoms and, optionally, one hydroxylgroup. Typical alkyldimethyl betaines include decyl dimethyl betaine or2-(N-decyl-N, N-dimethyl-ammonia) acetate, coco dimethyl betaine or2-(N-coco N, N-dimethylammonio) acetate, myristyl dimethyl betaine,palmityl dimethyl betaine, lauryl dimethyl betaine, cetyl dimethylbetaine, stearyl dimethyl betaine, etc. The amidobetaines similarlyinclude cocoamidoethylbetaine, cocoamidopropyl betaine and the like. Apreferred betaine is coco (C₈ -C₁₈) amidopropyldi methyl betaine.

The metal or ammonium salt of an ethoxylated alkyl ether sulfate isdepicted by the formula:

    R-(OCHCH.sub.2).sub.n OSO.sub.3.sup.M

wherein n is about 1 to about 10, more preferably 1 to 3 and R is analkyl group having about 8 to about 18 carbon atoms, more preferably 12to 15 and natural cuts, for example, C_(12-14;) C₁₂₋₁₅ and M is a metalor ammonium cation most preferably sodium or ammonium. The mostpreferred embodiment is R is C₁₂₋₁₄ and X=1 to 3. The ethoxylated alkylether sulfate surfactant is present in the composition at aconcentration of about 8 to 16 wt. %, more preferably about 9 to 15 wt.%.

The ethoxylated alkyl ether sulfate may be made by sulfating thecondensation product of ethylene oxide and C₈₋₁₀ alkanol, andneutralizing the resultant product. The ethoxylated alkyl ether sulfatesdiffer from one another in the number of carbon atoms in the alcoholsand in the number of moles of ethylene oxide reacted with one mole ofsuch alcohol. Preferred ethoxylated alkyl ether sulfates contain 12 to15 carbon atoms in the alcohols and in the alkyl groups thereof, e.g.,sodium myristyl (3 EO) sulfate.

Ethoxylated C₈₋₁₈ alkylphenyl ether sulfates containing from 2 to 6moles of ethylene oxide in the molecule also are suitable for use in theinvention compositions. These surfactants can be prepared by reacting analkyl phenol with 2 to 6 moles of ethylene oxide and sulfating andneutralizing the resultant ethoxylated alkylphenol.

All of the aforesaid three ingredients in this light duty liquiddetergent are water soluble or water dispersible and remain so duringstorage.

This particular combination of ethoxylated alkyl ether sulfatesurfactant, and betaine surfactant, provides a detergent system whichcoacts with the nonionic surfactant to product a liquid detergentcomposition with desirable foaming, foam stability and detersiveproperties. Surprisingly, the resultant homogeneous liquid detergentcomposition exhibits the same or better foam performance, both as toinitial foam volume and stability of foam in the presence of soils, andcleaning efficacy as an anionic based light duty liquid detergent (LDLD)composition as shown in the following Examples.

The essential three ingredients discussed above are solubilized in anaqueous medium comprising water and optionally, solubilizing ingredientssuch as alcohols and dihydroxy alcohols such as C2-C3 mono- anddi-hydoroxy alkanols, e.g. ethanol, isopropanol and propylene glycol.Suitable water soluble hydrotropic salts include sodium, potassium,ammonium and mono-, di- and triethanolammonium salts of benzenesulfonate or xylene sulfonate. While the aqueous medium is primarilywater, preferably said solubilizing agents are included in order tocontrol the viscosity of the liquid composition and to control lowtemperature cloud clear properties. Usually, it is desirable to maintainclarity to a temperature in the range of 5° C. to 10° C. Therefore, theproportion of solubilizer generally will be from about 0.5% to 8%,preferably 1% to 7%, by weight of the detergent composition with theproportion of ethanol, when present, being 5% of weight or less in orderto provide a composition having a flash point above about 46° C.Preferably the solubilizing ingredient will be propylene glycol. Anotherextremely effective solubilizing or cosolubilizing agent used at aconcentration of about 0.1 to 5 wt. percent, more preferably about 0.5to 4.0 weight percent is isethionic acid or an alkali metal salt ofisethionic acid having the formula

    CH.sub.2 OHCH.sub.2 SO.sup.-.sub.3.sup.+ X

wherein X is hydrogen or an alkali metal cation, preferably sodium.

The foregoing solubilizing ingredients also facilitate the manufactureof the inventive compositions because they tend to inhibit gelformation.

In addition to the previously mentioned essential and optionalconstituents of the light duty liquid detergent, one may also employnormal and conventional adjuvants, provided they do not adversely affectthe properties of the detergent. Thus, there may be used variouscoloring agents and perfumes; ultraviolet light absorbers such as theUvinuls, which are products of GAF Corporation; sequestering agents suchas ethylene diamine tetraacetates; magnesium sulfate heptahydrate;pearlescing agents and opacifiers; pH modifiers; etc. The proportion ofsuch adjuvant materials, in total will normally not exceed 15% of weightof the detergent composition, and the percentages of most of suchindividual components will be about 0.1% to 5% by weight and preferablyless than about 2% by weight. Sodium formate can be included in theformula as a perservative at a concentration of 0.1 to 4.0%. Sodiumbisulfite can be used as a color stabilizer at a concentration of about0.01 to 0.2 wt. %. Typical perservatives are dibromodicyano-butane,citric acid, benzylic alcohol and poly (hexamethylene-biguamide)hydro-chloride and mixtures thereof. The instant compositions cancontain 0 to about 2.5 wt. %, more preferably about 0.025 to about 2.0wt. %, most preferably about 0.05 to about 1.0 wt. % of an antibacterialagent. A preferred antibacterial agent is trichlorohydroxydiphenylether.

The instant compositions can contain about 0 to about 5 wt. %, morepreferably 1 to 4.0 wt. % of an alkyl polysaccharide surfactant. Thealkyl polysaccharides surfactants, which are used in conjunction withthe aforementioned surfactant have a hydrophobic group containing fromabout 8 to about 20 carbon atoms, preferably from about 10 to about 16carbon atoms, most preferably from about 12 to about 14 carbon atoms,and polysaccharide hydrophilic group containing from about 1.5 to about10, preferably from about 1.5 to about 4, most preferably from about 1.6to about 2.7 saccharide units (e.g., galactoside, glucoside, fructoside,glucosyl, fructosyl; and/or galactosyl units). Mixtures of saccharidemoieties may be used in the alkyl polysaccharide surfactants. The numberx indicates the number of saccharide units in a particular alkylpolysaccharide surfactant. For a particular alkyl polysaccharidemolecule x can only assume integral values. In any physical sample ofalkyl polysaccharide surfactants there will be in general moleculeshaving different x values. The physical sample can be characterized bythe average value of x and this average value can assume non-integralvalues. In this specification the values of x are to be understood to beaverage values. The hydrophobic group (R) can be attached at the 2-, 3-,or 4- positions rather than at the 1-position, (thus giving e.g. aglucosyl or galactosyl as opposed to a glucoside or galactoside).However, attachment through the 1- position, i.e., glucosides,galactoside, fructosides, etc., is preferred. In the preferred productthe additional saccharide units are predominately attached to theprevious saccharide unit's 2-position. Attachment through the 3-, 4-,and 6- positions can also occur. Optionally and less desirably there canbe a polyalkoxide chain joining the hydrophobic moiety (R) and thepolysaccharide chain. The preferred alkoxide moiety is ethoxide.

Typical hydrophobic groups include alkyl groups, either saturated orunsaturated, branched or unbranched containing from about 8 to about 20,preferably from about 10 to about 18 carbon atoms. Preferably, the alkylgroup is a straight chain saturated alkyl group. The alkyl group cancontain up to 3 hydroxy groups and/or the polyalkoxide chain can containup to about 30, preferably less than about 10, alkoxide moieties.

Suitable alkyl polysaccharides are decyl, dodecyl, tetradecyl,pentadecyl, hexadecyl, and octadecyl, di-, tri-, tetra-, penta-, andhexaglucosides, galactosides, lactosides, fructosides, fructosyls,lactosyls, glucosyls and/or galactosyls and mixtures thereof.

The alkyl monosaccharides are relatively less soluble in water than thehigher alkyl polysaccharides. When used in admixture with alkylpolysaccharides, the alkyl monosaccharides are solubilized to someextent. The use of alkyl monosaccharides in admixture with alkylpolysaccharides is a preferred mode of carrying out the invention.Suitable mixtures include coconut alkyl, di-, tri-, tetra-, andpentaglucosides and tallow alkyl tetra-, penta-, and hexaglucosides.

The preferred alkyl polysaccharides are alkyl polyglucosides having theformula

    R.sub.2 O(C.sub.n H.sub.2n O).sub.r (Z).sub.x

wherein Z is derived from glucose, R is a hydrophobic group selectedfrom the group consisting of alkyl, alkylphenyl, hydroxyalkylphenyl, andmixtures thereof in which said alkyl groups contain from about 10 toabout 18, preferably from about 12 to about 14 carbon atoms; n is 2 or 3preferably 2, r is from 0 to 10, preferable 0; and x is from 1.5 to 8,preferably from 1.5 to 4, most preferably from 1.6 to 2.7. To preparethese compounds a long chain alcohol (R₂ OH) can be reacted withglucose, in the presence of an acid catalyst to form the desiredglucoside. Alternatively the alkyl polyglucosides can be prepared by atwo step procedure in which a short chain alcohol (R₁ OH) can be reactedwith glucose, in the presence of an acid catalyst to form the desiredglucoside. Alternatively the alkyl polyglucosides can be prepared by atwo step procedure in which a short chain alcohol (C₁₋₆) is reacted withglucose or a polyglucoside (x=2 to 4) to yield a short chain alkylglucoside (x=l to 4) which can in turn be reacted with a longer chainalcohol (R₂ OH) to displace the short chain alcohol and obtain thedesired alkyl polyglucoside. If this two step procedure is used, theshort chain alkylglucosde content of the final alkyl polyglucosidematerial should be less than 50%, preferably less than 10%, morepreferably less than about 5%, most preferably 0% of the alkylpolyglucoside.

The amount of unreacted alcohol (the free fatty alcohol content) in thedesired alkyl polysaccharide surfactant is preferably less than about2%, more preferably less than about 0.5% by weight of the total of thealkyl polysaccharide. For some uses it is desirable to have the alkylmonosaccharide content less than about 10%.

The used herein, "alkyl polysaccharide surfactant" is intended torepresent both the preferred glucose and galactose derived surfactantsand the less preferred alkyl polysaccharide surfactants. Throughout thisspecification, "alkyl polyglucoside" is used to include alkylpolyglycosides because the stereochemistry of the saccharide moiety ischanged during the preparation reaction.

An especially preferred APG glycoside surfactant is APG 625 glycosidemanufactured by the Henkel Corporation of Ambler, Pa. APG25 is anonionic alkyl polyglycoside characterized by the formula:

    C.sub.n H.sub.2n+1 O(C.sub.6 H.sub.10 O.sub.5).sub.x H

wherein n=10 (2%); n=122 (65%); n=14 (21-28%); n=16 (4-8%) and n=18(0.5%) and x (degree of polymerization) =1.6. APG 625 has: a pH of 6 to10 (10% of APG 625 in distilled water); a specific gravity at 25° C. of1.1 g/ml; a density at 25° C of 9.1 lbs/gallon; a calculated HLB of 12.1and a Brookfield viscosity at 35° C., 21 spindle, 5-10 RPM of 3,000 to7,000 cps.

The instant compositions can contain a silk derivatives as part of thecomposition and generally constitute about 0.01 to 3.0 % by weight,preferably about 0.1 to 3.0% by weight, most preferably 0.2 to 2.5% byweight of the liquid detergent composition.

Included among the silk derivatives are silk fibers and hydrolyzate ofsilk fibers. The silk fibers may be used in the form of powder inpreparing the liquid detergent or as a powder of a product obtained bywashing and treating the silk fibers with an acid. Preferably, silkfibers are used as a product obtained by hydrolysis with an acid, alkalior enzyme, as disclosed in Yoshiaki Abe et al., U.S. Pat. No. 4,839,168;Taichi Watanube et al., U.S. Pat. No. 5,009,81 3; and Marvin E.Goldberg, U.S. Pat. No. 5,069,898, each incorporated herein byreference.

Another silk derivative which may be employed in the composition of thepresent invention is protein obtained from degumming raw silk, asdisclosed, for example, in Udo Hoppe et al., U.S. Pat. No. 4,839,165,incorporated herein by reference. The principal protein obtained fromthe raw silk is sericin which has an empirical formula of C₁₅ H₂₅ O₃ N₅and a molecular weight of 323.5.

Another example of a silk derivative for use in the liquid detergentcomposition of the present invention is a fine powder of silk fibroin innonfibrous or particulate form, as disclosed in Kiyoshi Otoi et al.,U.S. Pat. No. 4,233,21 2, incorporated herein by reference.

The fine powder is produced by dissolving a degummed silk material in atleast one solvent selected from, for example, an aqueous cupriethylenediamine solution, an aqueous ammoniacal solution of cupric hydroxide, anaqueous alkaline solution of cupric hydroxide and glycerol, an aqueouslithium bromide solution, an aqueous solution of the chloride, nitrateor thiocyanate of calcium, magnesium or zinc and an aqueous sodiumthiocyanate solution. The resulting fibroin solution is then dialyzed.The dialyzed aqueous silk fibroin solution, having a silk fibroinconcentration of from about 3 to 20% by weight, is subjected to at leastone treatment for coagulating and precipitating the silk fibroin, suchas, for example, by the addition of a coagulating salt, by aeration, bycoagulation at the isoelectric point, by exposure to ultrasonic waves,by agitation at high shear rate and the like.

The resulting product is a silk fibroin gel which may be incorporateddirectly into the liquid detergent composition or the same may bedehydrated and dried into a powder and then dissolved in the liquiddetergent composition.

The silk material which may be used to form the silk fibroin includescocoons, raw silk, waste cocoons, raw silk waste, silk fabric waste andthe like. The silk material is degummed or freed from sericin by aconventional procedure such as, for example, by washing in warm watercontaining a surfact-active agent or an enzyme, and then dried. Thedegummed material is dissolved in the solvent and preheated to atemperature of from 60° to 95° C, preferably 70° to 85° C. Furtherdetails of the process of obtaining the silk fibroin are discussed inU.S. Pat. No. 4,233,212.

A preferred silk derivative is a mixture of two or more individual aminoacids which naturally occur in silk. The principal silk amino acids areglycine, alanine, serine and tyrosine.

A silk amino acid mixture resulting from the hydrolysis of silk of lowmolecular weight and having a specific gravity of at least 1 is producedby Croda, Inc. and sold under the trade name "CROSILK LIQUID" whichtypically has a solids content in the range of about 27 to 31% byweight. Further details of the silk amino acid mixture can be found inWendy W. Kim et al., U.S. Pat. No. 4,906,460, incorporated herein byreference. A typical amino acid composition of "CRO SILK LIQUID" isshown in the following Table.

    ______________________________________                   PERCENT BY    AMINO ACID     WEIGHT    ______________________________________    Alanine        28.4    Glycine        34.7    Valine         2.0    Leucine        1.2    Preline        1.2    Tyrosine       0.6    Phenylalanine  0.9    Serine         15.4    Threonine      1.9    Arginine       1.5    Aspartic Acid  4.7    Glutamic Acid  4.1    Isoleucine     0.8    Lysine         1.4    Histidine      0.8    Cystine        0.1    Methionine     0.2    TOTAL          99.9    ______________________________________

The instant compositions can contain a viscosity modifying solvent at aconcentration of about 0.1 to 5.0 weight percent, more preferably about0.5 to 4.0 weight percent. The viscosity modifying agent is an alcoholof the formula ##STR3## wherein R₁ =CH₃, CH₂ CH₃

R₂ =CH₃, CH₂ CH₃

R₃ =CH₂ OH, CH₂ CH₂ OH;

which is preferably 3-methyl-3-methoxy-butanol.

The 3-methyl-3-methoxy butanol is commercially available from SattvaChemical Company of Stamford, Connecticut and Kuraray Co., Ltd., Osaka,Japan.

The instant composition can contain about 0.1 to 4.0% of a proteinselected from the group consisting of hydrolyzed animal collagen proteinobtained by an enzymatic hydrolysis, lexeine protein, vegetal proteinand hydrolyzed wheat protein and mixtures thereof.

The present light duty liquid detergents such as dishwashing liquids arereadily made by simple mixing methods from readily available componentswhich, on storage, do not adversely affect the entire composition.However, it is preferred that the nonionic surfactant be mixed with thesolubilizing ingredients, e.g., ethanol and, if present, prior to theaddition of the water to prevent possible gelation. The nonionic basedsurfactant system is prepared by sequentially adding with agitation theanionic surfactant and the betaine to the nonionic surfactant,cosolubilizing agent and water, and then adding with agitation theformula amount of water to form an aqueous solution of the surfactantsystem. The use of mild heating (up to 100° C.) assists in thesolubilization of the surfactants. The viscosities are adjustable bychanging the total percentage of active ingredients. No polymeric orclay thickening agent is added. In all such cases the product made willbe pourable from a relatively narrow mouth bottle (1.5 cm. diameter) oropening, and the viscosity of the detergent formulation will not be solow as to be like water. The viscosity of the detergent desirably willbe at least 100 centipoises (cps) at room temperature, but may be up toabout 1,000 centipoises as measured with a Brookfield Viscometer using anumber 3 spindle rotating at 18 rpms. Its viscosity may approximatethose of commercially acceptable detergents now on the market. Thedetergent viscosity and the detergent itself remain stable on storagefor lengthy periods of time, without color changes or settling out ofany insoluble materials. The pH of this formation is substantiallyneutral to skin, e.g., about 4.5 to 8 and preferably about 5 to about5.5. The compositions of the instant invention are optically clear--thatis they exhibit a light transmission of at least 95%, more preferably atleast 98%.

These products have unexpectedly desirably properties. For example, thefoam quality and detersive property is equal to or better than standardlight duty liquid detergents while using a nonionic surfactant as theprimary surfactant and minimal amounts of anionic surfactant, therebyachieving a mild, non-irritating liquid detergent.

The following examples are merely illustrative of the invention and arenot to be construed as limiting thereof.

EXAMPLE 1

The following formulas were prepared at room temperature by simpleliquid mixing procedures as previously described.

    ______________________________________                    A      B        C    ______________________________________    NEODOL 1-9        15.5     12.5     14.5    Cocoamidopropyl   7        5.5      7    Betaine    Sodium salt of ethoxylated alkyl                      11.5     10.5     10.5    ether sulfate surfactant (1.3 EO)    Sodium Bisulfite  0.05     0.05     0.03    Perfume           0.2      0.2      0.2    Water             Balance  Balance  Balance    Monoethanol amide 0        1.5      --    MgSO.sub.4.7H.sub.2 O                      3.1      3.1      3.5    HEDTA             0.08     0.08     0.08    Sodium Formate    2.0      2.0      2.0    Shell Foam        +        S        S    Shake foam "Foam Height"                      5        S        S    Brookfield viscosity LVTDV                      410      350      428    RT, #3    spindle, 18 rpms (cps)    ______________________________________

The Shell Foam and Shake Foam Height test were run against a controlsample of a commercial Palmolive Skin Sensitive formulation manufacturedby Colgate-Palmolive Co. The designation "s" means that the sample beingtested has the same value as the commercial sample. The designation "-"means that the value obtained is less than the value obtained for thecommercial sample. The designation "+" means that the value obtained issuperior to the value obtained for the commercial sample.

What is claimed is:
 1. A high foaming light duty liquid detergentcomposition consisting essentially of:(a) 13% to 25% of a water solublenonionic surfactant selected from the group consisting of primary andsecondary C8-C18 alkanol condensates with 5 to 30 moles of ethyleneoxide, condensates of C8-C18 alkylphenol with 5 to 30 moles of ethyleneoxide and propylene oxide having a weight ratio of total alkylene oxidecontent of 60% to 85% by weight and condensates of 2 to 30 moles ofethylene oxide with sorbitan mono and tri-C10-C20 alkanoic acid estershaving an HLB of 8 to 15, said nonionic surfactant consisting of theprimary surfactant and major ingredient in said detergent composition;(b) 2% to 12% of a water-soluble betaine; (c) 8% to 16% of a metal orammonium salt of an ethoxylated alkyl ether sulfate; and (d) the balancebeing water as an aqueous medium in which said nonionic surfactant, saidmetal or ammonium salt of said ethoxylated alkyl ether sulfate and saidbetaine are solubilized in said water, wherein the composition does notcontain any amine oxide, clay fatty acid or a metal salt of a fattyacid, sulfonate surfactant, polymeric surfactant or an alkyl sulfatesurfactant, and the concentration of said nonionic surfactant is alwaysgreater than the concentration of said ethoxylated alkyl ether sulfatesurfactant and said betaine surfactant.
 2. A liquid detergentcomposition according to claim 1 further including about 1.0 to about15% of a cosolubilizing agent selected from the group consisting of C₂-C₃ mono- and di-hydroxy alkanols, water soluble salts of C₁ -C₃substituted benzene sulfonate hydrotropes and mixtures thereof.
 3. Aliquid detergent composition according to claim 2 wherein ethanol ispresent in the amount of 5% by weight or less.
 4. A liquid detergentcomposition according to claim 2 wherein said nonionic surfactant issaid condensate of a primary C₈ -C₁₈ alkanol with 5-30 moles of ethyleneoxide.
 5. A liquid detergent composition according to claim 1 furtherincluding 0.1 wt. % to 5.0 wt. % of a preservative being selected fromthe group consisting of sodium formate, dibromodicyanobutaine, citricacid, benzylic alcohol and poly (hexamethylene-biquamide) hydrochlorideand mixture thereof.
 6. A liquid detergent composition according toclaim 1 further including 0.1 wt. % to 5.0 wt. % of a color stabilizerwhich is sodium bisulfite.
 7. A liquid detergent composition accordingto claim 1 further including about 0.5 to about 8.0 wt. % of asolubilizing agent which is selected from the group consisting ofalcohols, dihydroxy alcohols, sodium, potassium ammonium and mono-, di-and triethanol ammonium salts of benzene sulfonate and xylene sulfonateand isethionic acid.
 8. A liquid detergent composition according toclaim 1 further including about 1 to about 4.0 wt. % of an alkylpolysaccharide surfactant.
 9. A liquid detergent composition accordingto claim 1 further including about 0.025 to about 2.0 weight percent ofan antibacterial agent which is trichlorohydroxydiphenyl ether.